This is really a one-woman crusade — the story of someone without a legal background who uses her intuition, common sense, moral outrage and lived experience as a single mother in difficult financial circumstances to take on a powerful corporation and win. It’s an updated, feminist David-and-Goliath story. The corporation has poisoned the local water supply, causing serious illness and cancer among residents, yet is determined to protect its own interests rather than acknowledge wrongdoing or pay the compensation that is clearly deserved.

The story unfolds in a slightly sprawling, almost episodic way against the backdrop of the California high desert. There’s a leisurely pace which, in some ways, is disarming, but it allows for rich detail — particularly in Erin’s personal life. Her relationship with her biker boyfriend is unconventional, with him ultimately taking on a more domestic role, caring for her children while she becomes consumed by the case.

What makes the film so effective is the way Erin connects with the community. She knocks on doors, memorises names and phone numbers, listens to people, and builds trust in a way that the trained lawyers simply cannot. She understands the people affected because she is, in many ways, one of them. The lawyers, by contrast, feel distant and out of touch. She may not have formal qualifications, but she does the real legwork, even if she doesn’t initially receive the financial recognition that might be expected.

Albert Finney gives one of his finest performances as her overworked, initially sceptical boss, who gradually comes to recognise both her ability and her tenacity. There is a sense of redemption in his arc, but Erin herself doesn’t soften or change course — if anything, she becomes more determined, more driven.

And while the film delivers a sense of justice, it’s not simply about a neat happy ending. What it ultimately suggests is that one victory leads to others — that this kind of fight doesn’t end, and that real change requires persistence, resilience and a refusal to back down.